Dryer is a Whirlpool GGQ9800LW1, about 20 years old. The belt broke, but the motor is also not spinning when it's turned on. No 60 hz hum either, and the armature spins freely when turned by hand.

The thermal fuse has continuity, and the door switch is fine -- turns on the light, and you can hear a relay click inside the control panel when you move the switch.

Where do I start troubleshooting? I can get parts diagram online, but not a circuit diagram, apparently.